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SD card redriver/buffer

CK Ho
Expert 1780 points
Other Parts Discussed in Thread: SN74AUC244, SN74AUC2G125, SN74AUC2G34

Dear team,

Our customer's PCB trace for SD card is too long.

Does TI have suggested redriver or buffer solution for this application??

Thank you very much.

  • 0
    TI__Guru* 96661 points
    Hi CK,
    Can you provide some details?

    How many channels must be buffered?
    What is the operating frequency (or bit rate)?
    What is the operating voltage?
  • 0 in reply to Emrys Maier
    Expert 1780 points

    Dear Emrys Maier,

    Thanks for your feedback.

    We need 6 channels: CLK/CMD/D0-D3 (parallel)

    Bit rate: 100Mbps (MAX)

    Operating voltage: 1.8V

  • 0 in reply to CK Ho
    TI__Guru* 96661 points
    I assume D0-D3 are bidirectional signals (read/write), and CLK/CMD are unidirectional signals, only going out to the SD card.

    I would recommend using 2 devices, an SN74AUC244 provides up to 8 channels of direction controlled buffers (the direction must be selected by an external controller). We do not have a 4 channel, so 8 is the closest match.

    The SN74AUC2G34 will provide 2 channels of unidirectional buffering. If you need the ability to put the outputs into high impedance (for example, when a card is removed) then you might consider the SN74AUC2G125 instead, which includes 3-state outputs.

    The AUC family is optimized for 1.8V operation and for relatively high-speed signals, which is why I would recommend it for this application.